1. Field of the Invention
The present invention relates generally to dental drills, and more particularly, to a method and apparatus for lubricating and disinfecting dental drills or other hand pieces having air turbine motors and which may include a water line for directing a stream of cooling water at a surface being drilled.
2. Description of the Prior Art
Dental drills and similar handpieces often include an air powered turbine head containing a turbine rotor which must be lubricated each day. At present, such daily lubrication requires that the supply hose, which provides pressurized air and water, and in some instances, a source of light, to the dental drill, be uncoupled from the drill so that an elongated, flexible nozzle of a lubricant spray container can be inserted into the air inlet opening of the dental drill that leads to the turbine rotor; the lubricant, typically oil, is then sprayed into the turbine area of the drill. Following lubrication, the supply hose must be reattached to the drill. Reattachment of the supply hose to the dental drill is delicate, taxing, and time-consuming; therefore, personnel assigned the task of lubricating such dental drills often neglect it, and expensive turbines burn out faster than expected.
Those skilled in the art have attempted to solve the problem of easily and effectively lubricating dental drills but have not been entirely successful. U.S. Pat. No. 3,879,851 to Landgraf discloses a device for lubricating dental drills with aerosol spray containers without disassembly of the drills prior to lubrication. The patent to Landgraf discloses an intermediate piece coupled between the turbine head and a hand grip. The intermediate piece includes a port normally sealed by a ball valve whenever the drill is operated. The nozzle of a lubricant container may be introduced into the port when the drill is not in use. However, the nozzle may not be advanced to any significant degree into the drill itself; therefore, the lubricant is not efficiently directed toward the turbine head and can dissipate inside the intermediate piece before reaching the turbine head.
U.S. Pat. No. 3,946,490 to Sotman et al. discloses a device for aerosol lubrication of dental drills. The Sotman device is a specially designed dental handpiece which includes a lubrication opening ordinarily sealed by a sliding clip or collar. A lubrication opening projects angularly into the turbine housing. During lubrication, a tube extending from the discharge port of an aerosol lubricant can is inserted through the lubrication opening; therefore, lubricant can be injected directly from the lubricant can into the turbine housing. However, the Sotman device requires substantial modification to conventional dental drill handpieces which lack such opening.
U.S. Pat. No. 4,218,216 to Sugai et al. discloses a lubrication device inserted between the end of a dental handpiece and the flexible service hose for permitting lubricant to be added to the air supply line. Rather than permitting periodic application of a lubricant from an aerosol spray container, the device disclosed by Sugai et al. continuously adds a mist oil to the compressed air channel. However, such constant lubrication poses a significantly greater risk of inadvertently injecting such lubricant into a patient's mouth as compared with the practice of periodically lubricating a dental handpiece once each day.
In addition, French Patent No. 2526-125 discloses an air motor for a dental handpiece including an air inlet and a separate lubricant branch within the motor body connected to the air inlet passage. The lubricant branch houses a spring loaded, normally closed ball non-return valve. Oil is injected into the lubricant branch, forcing open the ball non-return valve by the pressure of the lubricating device. However, the air motor disclosed within this French patent would require substantial modification of dental handpieces that are already heavily in use.
U.S. Pat. No. 4,490,113 to Kawada discloses a dental handpiece having a rotatable connector for allowing the dental handpiece to be more easily rotated about its axis. The connector includes a radial oiling filler and filler cap for oiling the dental handpiece.
Accordingly, it is an object of the present invention to provide a dental drill lubricating device for periodically lubricating dental drills without requiring disassembly of the dental drill from the associated supply hose.
It is another object of the present invention to provide such a dental drill lubricating device which can be used without modification of the dental handpiece itself.
It is still another object of the present invention to provide a dental drill lubricating device which permits the tip of the lubricant nozzle to be inserted into an air passage within the dental handpiece itself.
High-speed dental handpieces are in common use today because such high-speed handpieces can be used with less discomfort to the dental patient. Such high-speed dental handpieces typically include a water line in addition to pressurized air entry and exhaust lines extending therethrough from the turbine head end of the drill to the opposing hook-up end of the drill that is adapted to mate with the above-described supply hose. The water line terminates in a small nozzle which directs a cooling stream of water at the surface that is being drilled to prevent the build-up of heat which can cause patient discomfort. The control unit operated by the dentist or dental technician (by a foot pedal or otherwise) is adapted to simultaneously start and stop the flow of water each time the drill is operated.
It is believed that each time that the cooling water stream is suddenly shutoff, as when the controlling foot pedal is released, a negative pressure, or back pressure, can develop within the water line of the dental handpiece. It is feared that this negative pressure can actually suction oral fluids from a patient's mouth into the water emitting nozzle of the dental handpiece and into the water line of the handpiece. This potential problem has become of such concern that some cities and municipalities are actually requiring dental offices to install intricate antisyphon devices within their dental offices to prevent any backflow of water being supplied to the dental office from contaminating municipal water supply lines.
Likewise, there is a possibility that negative pressure can develop within the pressurized air inlet and air exhaust lines communicating with the air turbine head of the dental handpiece when the pressurized air supply is released between actuations, and that such negative pressure can similarly suction oral fluids into such lines.
Particularly in view of the recent epidemic of AIDS, dentists and dental technicians have become increasingly aware of the possibility of transmitting diseases from one patient to the next. It is now common for dental technicians to spray a bactericide upon the outer surfaces of dental handpieces and upon the dental chair, as well as to wipe dental drill pieces with alcohol, in order to help prevent the spread of infection from one patient to the next. However, such measures do not effectively neutralize bacteria or viral matter which may have been suctioned into the water and air lines within the dental handpiece itself. While some dental handpieces may be autoclaved to ensure sterility, thousand of dental handpieces are in use which can not be autoclaved because they are incapable of withstanding such high temperatures.
In theory, access to the air inlet, air exhaust, and water lines of the dental handpiece can be obtained by uncoupling the supply hose from the hook-up end of the dental handpiece. However, as noted above, the removal and reattachment of the dental handpiece from the supply hose is a taxing job. If the dental handpiece had to be removed from the supply hose for disinfection purposes between every patient procedure, then the dental office could not attend to as many patients each day.
Accordingly, it is an object of the present invention to provide a dental handpiece disinfection device for allowing the interior passageways of a dental handpiece to be easily and conveniently disinfected between patient procedures without requiring the disassembly of the dental handpiece from its associated supply hose.
It is another object of the present invention to provide such a dental handpiece disinfection device which can be used without modification of the dental handpiece itself.
It is still another object of the present invention to provide such a disinfection device which allows a disinfectant to be introduced into either or both of the pressurized air lines and cooling water line that extend within the dental handpiece.
It is a further object of the present invention which further facilitates the periodic lubrication of the air powered turbine head of the handpiece.
A still further object of the present invention is to provide a convenient method for disinfecting the interior passages of a dental handpiece between successive patient procedures.
Other objects, advantages and features of the present invention will become more apparent to those skilled in the art from the following specification when taken in conjunction with the accompanying drawings.